Process for improving textiles



Matien-isacontinuation-in-part of our copending application Serial No. 322,766, filed Patented 8, 1942 mocnss FOR IMPROVING 'rnxmns Max Engelmann, Wilmington, DeL, and Josef Pikl, Pitman,

N. J., assignors to E. I. du Pont de Nemours & Company, Wilmington, DeL, a corporation of Delaware No Drawing. Application October 2, 1940,

Serial 'No. 359360 13 Claims. (01. 8-116) March 7, 1940, and relates to a process for treating fibrous materials to modify their surface characteristics.

It is an object of this invention to provide a process for imparting water-repellency and softness of feel to fibrous material of vegetable, animal or synthetic origin, using the novel phosphonic acid compounds described and claimed in said copending application. Other and further important objects of this invention, will appear as the description proceeds;

R" is a long-chain aliphatic radical.

As a special subgroup under the above 'general formulas come into consideration thos :com-

' pounds wherein R contains an aliphatic or cy- In our copending application, Serial No. 322,766,

above referred to We have described a series of novel organic compounds which may be designated generally as acyl-amido-methylene phosphonic acids. They are synthesized from methylol-amides of carboxylic acids by reacting upon the latter with a phosphorus trihalide to produce an intermediate phosphorus halide compound, and then decomposing the latter by water (or atmospheric humidity) to giv a phosphonic acid. The general scheme of Synthesis and the resulting products is typifiedvby the following equations:

RN-CHiOH+PCii phosphonic acid In these formulas, R stands for hydrogen or a 1 lower alkyl radical, while R designates any organic radical whatsoever which is linked to the N atomthrough the keto group (CO) or the thione group (CS). Thus, R may stand for the grouping cloaliphatic radical of at least 10 carbon atoms. The members of this subgroup have the common property of modifying the surface characteristics of textile fibers, bestowing upon the same a soft feel and the quality of water-repellence. Depending upon the mode of treatment, both of these properties can be rendered substantially permanent in the sense that the efiect is not substantially impaired by laundering and dry-cleaning.

The method or synthesis or the novel compounds has been described in detail in our parent application above referred to, and therefore need not be taken up in detail her Our present invention is concerned primarily with the utilization of these novel compounds for thepurpose of modifying the surface characteristics of fibrous materials. We have found that the above special group of compounds which are obtained from amides having an aliphatic or cycloaliphatic radical, in their structure, of from 10 to 28 carbon atoms are very active as softening agents and water-repellency agents for textile fiber. Moreover, althouglrbut sparingly soluble in the form of free phosphonic acid, they may be readily converted into water-soluble salts by neutralization of the phosphonic OH groups, individually Or Jointly, with alkali-metal hydroxides, or with ammonia and organic amines. In a number of cases, we have actually prepared and isolated the sodium, ammonium, diethanolammonium and pyridinium salts. v

These salts, especially the ammonium salts, are very convenient agents for application to the fiber from an aqueous bath. However, it is not necessary to prepare and isolate these salts in substance, inasmuch -as it is suflicient to dissolve the free phosphonic acids in an aqueous bath containing an inorganic or organic base, for instance vsodiumhydroxide, ammonia, pyridine or mono-.

or triethanolamine. Moreover, good results may also be obtained by using the free phosphonic acids in the absence of alkalies, inasmuch as with both softness and water-repellency. A concentration of 0.5 to 5% by weight of the aqueous bath will generally give satisfactory results for the solubility of these acids is often as high as I water-repellency plus incidental softness, while for softness alone even a concentration as low as 0.01% has been found effective.

The treatment generally consists of impregnating the fiber with the aqueous bath atroom temperature or slightly elevated temperature, say up to 45 or 50 C. The fiber is then squeezed out or centrifuged until it retains just about its own weight of the impregnating solution. It is then optionally dried at a temperature, say, below 70 C., and then subjected to a baking treatment at a temperature between 90 and 200 0., preferably between 100 and 170 C., for a period of time which varies somewhat inversely with the temperature as more fully explained hereinbelow.

In the case of treatment for softness alone, we have found it advantageous to subject the fabric after baking to a soaping treatment in an aque ous bath containing a true soap, that is an alkalimetal or equivalent salt of a fatty acid. A conc'entration of 0.1 to 1% of the soap has been found by us satisfactory for this purpose.

Without limiting our invention to any particular procedure, the following examples are given to illustrate our preferred mode of operation. Parts mentioned are by weight.

Example 1 .100 parts of methylol stearamide were added to a mixture of 45 parts of carbon tetrachloride and 91 parts of phosphorus trichloride. One hour after all the methylol amide had been added, 40 parts of acetic acid were added and the reaction mass was allowed to stand at room temperature for four days. The reaction mixture gradually became a viscous mass and at the same time soluble in dilute alkalies. posed with 8% hydrochloric acid at about 50 C. and yielded a crystalline readily filterable product which could be recrystallized from alcohol It Example 2 30 parts of methylol stearamide were suspended in 300 parts of ethyl acetate and at 25 C. 17 parts of phosphorus tribromide added. When the reaction mass was warmed to 40 C. a-clear solution resulted. It was held at 40 to 45 C. for two hours then allowed to cool to room temperature. After 14 hours a crystalline product had separated which was filtered off. decomposed with water and crystallized from alcohol. The product was identical with the compound prepared according to Example 1, and produced upon cotton the same effect.

Example 3 45 parts of methylol amide from a mixture of carboxylic acids having 20 and 22 carbon atoms was added to 100 parts of phosphorus trichloride at room temperature and agitated for 1 hour. 38 parts of acetic acid was added and then allowed to stand at room temperature for 3 days. The hard reaction product was broken up and de-' composed by ice and then filtered. The product dissolved in methyl alcohol on warming to an al- The product was decommost clear solution and crystallized again on cooling. The product was soluble in water containing a small amount of a monia or pyridine.

When a piece of cotton cloth was padded in, a 2% solution of this product in water containing 0.5% ammonia and then heated for 5 minutes C. the cloth became water-repellent and towards washing.

Example 4 Naphthenic acid amide was converted into the corresponding methylol compound by reacting the amide with formaldehyde in an 32 parts of the oily methylol naphthene amide were mixed with 27parts of P013 and 24 parts of acetic acid and then allowed to stand at room temperature for several days. The reaction mass was decomposed with ice and the oily bottom layer taken up with petroleum ether. Upon evaporation of the solvent a thick orange colored oil was left which was soluble in warm water and in dilute alkalies. It contained the expected amount of phosphorus and nitrogen. This product exhibited strong antioxidant and metal-deactivating properties', deactivating metals such as iron, manganese, cobalt and copper.

When an ammoniacal solution was applied to cotton or rayon and the cloth heated for a few minutes to temperature of to C. it became water-repellent and soft but not as marked as when treated with products of Example 1.

Example 5,

32 parts of hydroabietic acid methylol amide were added at room temperature to 30 parts of phosphorus trichioride, and 16 parts of acetic acid were added and the reaction mass allowed to stand at room temperature for several days. The originally thin mass gradually became a hard product which could not be stirred, When the reaction was completed the condensation product was treated with 250 parts of water, and the past? product was taken up with ether. Upon evaporation of the ether a hard mass remained which could be pulverized. It was solubl in dilute alkalies and had strong foaming properties.

When an ammoniacal solution was applied to cotton 'or rayon and the cloth heated for a few minutes to temperature of 120 to 170 C., it became water-repellent and soft .but not as marked as when treated with products of Example 1.

Example 6 50 parts of methylol octadecyl carbamate as prepared according to French Patent No. 840,002 were added to 100 parts of ride at room temperature. After agitating for 1 hour, 38 parts of acetic acid were added and the reaction mass allowed to stand at room temperature for several days. The hard reaction mass was broken up, decomposed by ice and then filtered. By purification with methyl alcohol a small amount of an insoluble material was removed. The main fraction was very soluble in dilute aqueous ammonia. The analysis corresponded to that of the expected compound of the formula C nHar-O-C o H When applied to cotton in the way as desc ibed in Example 1, it imparted to the fabric a strongly base like NaOH, am-

alcoholic solution. 4

phosphorus trichlosolution which was obtained I asoaiov' water-repellent, soft finish. Instead of the moth ylol octadecyl carbamato an equivalent amount or another oarbamate of a higher or lower molecular weight maybe used. such as the corresponding tetradecyl carbamate, hexadeoyl carbamote. or octadecyl-phenyl carbamate.

Ewcmple 7 g 8 parts of the dimethylol amide of methylene distearamide, which was prepared by decomposing methylene-bis-(stearamidomethyl-chloride) (British Patent No. 517,474) with 50% KzCOs at low temperature, were added to'20 parts of P013 at room temperature. To the clear thin in a few minutes, parts of acetic acid were added. Upo'n standing at room temperature over night, the mass solidified to a very thick plastic mass which dissolved in ammoniacal water to a clear'solution.

The product was decomposed with water and then purified by dissolving it in dilute ammonia, filtering out someinsoluble material and precipitat ng the phosphonic acid from the alkaline solution with hydrochloric acid. In this way a product was secured which dissolved to a perfectly clear solution in warm water containing,

a small amount of a base.

Cotton cloth and rayon tafieta were impreg nated with a 1% solution of the ammonium salt of this phosphonic acid and then heated to 150 C. for a few minutes. After this baking treatment the goods were washed with sodium oleate soap and dried. Both samples showed a very soft feel and a strong water-repellency.

The dimethylol amide used as initial material in this example is a new compound and is further described and 01a ed in copending application of Josef Pikl, Serial No. 362,790.

Example 8 10 parts of the product prepared according to Example 1 was dissolved in 1000 parts of water with the aid of some ammonia. Cotton broad cloth was impregnated with this solution and dried for 10 minutes at 165 C. then washed for five minutes at 180 C. in'a 0.5% solution of and dried.

is not so critical sodium oleate and finally-rinsed inhot water,

-, The cloth acquired a very soft feel.

Example 9 Viscose process rayon yarn was impregnated with a solution of stearamidomethyl phosphonic not per liter; the yarn was then dried at room temperature and heated for 5 minutes to 140 C.

. acid (Example 1) containing 0.1 part of the prod- After the baking, the yarn had a soft touch but showed only a little water-repellency. It was now washed for 15 minutes in 72% solution of oleic-acid soap and rinsed in hot this washing treatment.

. wa dfi li ho;.= softness of the yarn was greatly improved by weaken the fiber, in the exposure to the acids liberated in the baking step.

moisture, the fiber shall'contain the other in from 1 to i% of its own weight. Thus, if the fiber is squeezed until it contains its own weight of moisture, the concentration of the both may be from 1 to 4%. But if the fiber is squeezed until the pick-up is only 50% of its dry weight, the initial concentration of the treatment both should be twice as high. l

Formaldehyde, dimethylol urea or other agents yielding formaldehyde in aqueous solution may be added to the bath ness and the permanence'of the resulting treatment, in accordance of O. C. Bacon, Serial No. 336,375. The quantity added may vary from 0 to 3% by weight of the total bath. Higher concentrations may be employed provided a tertiary amine is employed instead of ammonia for s'olubilizing the phosphonic acid.

The temperature of impregnation may be varied from room temperature to "about 45 or 50 C. Lower or higher temperatures may be used, but there is no apparent advantage. I As already indicated, the intermediate drying step may be employed or omitted, since the presence of moisture during the baking treatment here as in the case of octadecyloxy-methyi-pyridinium chloride, for instance. I

The baking temperature may vary from to 200 C. but is usually more conveniently selected between and C. The time required for baking varies may be as high as 30 the lower temperature limit and as minute at the for any given-reagent and temperature combination may be determined experimentally 'by treating samples of the chosen fabric and then estimating, by the usual tests, the intensity and durability of the water-repellent efiect bestowed on it. Time periods in excess of the optimum do not affect the water-repellency, but tend to case of cellulose, due to minutes at low as In other details, our'novel process may follow in general the hitherto established processes for waterproofing fiber with quaternary ammonium compounds as typified by cetyloxy-methyl pyridinium chloride and stearamido methyl pyridinium chloride.

We claim: I

l A process for treating textile fiber for the purpose of modifying the surface characteristics thereof, which comprises impregnating the same with a compound selected from the group con- It will beunderstood, that although our ape cific examples above dealt particularly with the treatment of cotton and rayon, this invention is applicable also to the waterproofing of animal fibers, such as wool, silk, leather; of synthetic fiber, such as regenerated cellulose, nylon; and to non-fibrous cellulosic films, such as Cellophane. Furthermore, the details of procedure may be varied within wide limits without departing from the spirit of this invention,

Thus, the concentration of the amide-methylene. phosphonic acid salt in the treatment bath may yary from 1 to 8% by weight. A good rule to follow is to use such a concentration that sisting of the free methylenesphosphonio acid selected-"from the group of spending to the formulas- RN.CH;- PO(OH)s and R-Jf-CHr-PMOH):

1m RN-CHs-P0(0H)s wheiiein R stands for a substituent of the group consisting of hydrogen is an organic radical containing a chain of not less than 10 carbon atoms, but being free from water-solubilizing groups and being attached to the N -atom, through the agency of a ketonic link selected from the group consisting of C==O and to increase its efiectivewith copending application somewhat inversely with the temhigher limit. The optimum time" compounds correand lower alkyl, while P.

wherein R is a radical C== S; and then subjecting the impregnated fiber to the action of heat at a temperature between 90 and 200 C.

2. A process as in claim 1 including further the step of subjecting the fiber after heat-treatment to the action of an aqueous bath containing a soap of a fatty acid.-

3. A process for treating textile fiber for the purpose of modifying the surface characteristics thereof, which comprises impregnating the same with a water-soluble salt of an amido-methylenephosphonic acid selected from the group of compounds corresponding to the formulasand n"oo-Nonr-ro on i tn, w-oo-fr-om-rowmi wherein'R stands for a substituent of the group consisting of hydrogen and lower alkyi, while R" is an organic radical containing a saturated carbon chain of not less than carbon atoms,

the same with an aqueous solution of a salt of an amido-methyiene-phosphonic acid of the general formula Alk-CONH-CI-I-PO(OH):, wherein All: designates an alkyl radical of from 10 to 28 carbon atoms; removing excess moisture, and then subjecting the fiber to a heat treatment at a temperature between 100 and 170 C. for a period of time sufiicient 'to cause decomposition of said amido-methylene phosphonic acid compound.

8. A process as in claim 5, wherein the aqueous solution employed for impregnation contains said amido-methylene-phosphonic acid compound in a concentration of from 0.5 to 5% by weight.

9. A process as in claim 5, wherein the aqueous solution employed for impregnation contains said amido-methylene-phosphonic acid compound in a concentration of from 0.01 to 0.5% by weight, the heat treatment being followed by a soaping treatment of the fiber in an aqueous solution of 5. A process for treating textile fiber for the purpose of modifying the surface characteristics thereof, which comprises impregnating the same with a salt of an amido-methylene-phosphonic acid of the general formula R--C0NH-'-CH2-PO (OH 2 wherein R is an organic radical containing a saturated carbon chain of not less than 10 carbon atoms, but being free from water-solubiiizing groups; and then subjecting the impregnated fiber to the actionof heat at a temperature between and 200 C.

6. A process for treating textile fiber for the V purpose of modifying the surface characteristics thereof, which comprises impregnating the same with a salt of an amido-methylene-phosphonic acid of the general formula selected from the group consisting of aliphatic and cycloaliphatic radia fatty acid soap.

10. A process for tre the purpose of modifying the surface characteristics thereof, which comprises impregnating the same with an aqueous solution of a salt of an amido-methyiene-phosphonic acid of the general formula v 'n-co-N-cm-rowmi wherein R is an organic radical containing an 35 aliphatic or cycloaliphatic group of from 10 to 28 carbon atoms; removing excess moisture, and

then' subjecting the fiber to a heat treatment at a temperature between and C. for a period of time sufilcient to cause decomposition of said ammo-methylene phosphonic acid com pound. 11. In a process of treating textile fiber to render the same water-repellent, the step which consists of impregnating the samewith an aqueous solution of the ammonium salt of stearamido-methylene-phosphonic acid, and then heating the fiber ii -the absence of moisture to decompose said agent on the fiber. r

- 12. In, a process of treating textile fiber to render the same water-repellent, the step which consists of impregnating the same with an aqueous solution of the ammonium salt of methylenebis (stearamido methylene phosphonic acid) and then heating the fiber in the absence of moiscals having from 10 to 28 carbon atoms and being free from water-solubilizing groups, Y is an atomic bridge selected from the group consisting oi CH2, 0, S, NH and CONH; and then subjecting the impregnated fiber to the action of heat at a temperature betweenlOO and 170 C.

'7. A process for treating cellulosic textile fiber for the purpose of modifying the surface characteristics thereof, which comprises impregnating ture to decompose said agent on the fiber.

13. In a process of treating textile fiber to endow the same with asoft feel, the improvement which consists of impregnating the same with anaqueous bath containing stearamido -methylphosphonic acid, and then heating the fiber in the absence of moisture to decompose said agent on the fiber.

MAX ENGELMANN. JOSEF PIKL.

ting cellulosic fiber for 

